Hydrostatic testing tool and methods of use

ABSTRACT

A hydrostatic testing tool for testing containers, hoses or the like under high pressures. The testing tool having a coupling that threadably engages a threaded aperture of a test container without having to be rotated into the threaded aperture. The hydrostatic testing tool may be hooked up to a source of pressurized medium and the tool includes a container-engaging head having a plurality of collet segments that each have a threaded surface that can expand radially outward, partially due to the force of the pressurized medium, to engage a threaded aperture of the test container, allowing for the formation of a liquid and/or gas tight seal under high pressures. The testing tool further includes an actuating unit connected to the head that controls the movement of the collet segments with a piston or the like.

RELATED APPLICATION

The present application is a continuation of U.S. patent applicationSer. No. 12/027,138, now U.S. Pat. No. 7,934,415, filed Feb. 6, 2008,which application claimed the benefit of U.S. Provisional ApplicationNo. 60/888,624, filed Feb. 7, 2007, both of which are hereinincorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to a hydrostatic testing tool.Particularly, the present invention relates to a hydrostatic testingtool having a coupling that threadably engages a threaded aperture of atest article without having to be rotated into the threaded aperture.More particularly, the present invention relates to a hydrostatictesting tool, which has a plurality of threaded collet segments that canexpand radially outward to engage a threaded aperture of a test articleto form a junction between the testing tool and the test article, whichprovides a liquid tight seal when the testing tool is operativelysecured to the test article.

2. Description of the Related Art

Hydrostatic testing tools are used for testing the strength andintegrity of test articles such as, metal bottles, containers, pressurecarrying hoses and the like, wherein the bottle, container or hosegenerally has a filler/discharge aperture with an internal, threadedfemale coupling.

Typical containers to be tested must be able to safely contain gases andliquids stored at high pressures. The containers have various commercialapplications but are often used, for example, in the medical equipmentindustry for storage of gases and gaseous liquids under high pressure.Typically, the containers will have an internal volume ranging betweenabout 0.5 cubic feet to about 1.5 cubic feet. The containers aregenerally tested for strength using pressures of more or less than about6000 pounds per square inch.

Each article to be tested will have an internal thread on itsfiller/discharge aperture. When these articles are tested, the testequipment is usually attached to the threaded aperture of the articlesin one of two known ways. The first method is to rotate a threaded endof the testing tool into the threaded aperture of the article to producea tight seal. This method generally requires complex automatic equipmentto do the threading and unthreading needed to connect the tool to thelarge quantity of articles that are typically tested in a given timeinterval. This could be done by hand, but however it is done, it isextremely time consuming and limits the rate of test production.

The second known method is to insert an expandable rubber plug into thethreaded aperture of the container and to then mechanically expand therubber plug to sealably engage the threaded aperture. This method hasnot been shown to provide a reliable seal between the test article andtesting tool.

The present invention addresses limitations and problems associated withthe prior art.

SUMMARY OF THE INVENTION

The present invention provides a hydrostatic testing tool for testing atest article, such as a container, having a threaded aperture. Thetesting tool comprising an actuator unit and a head interconnected tothe actuator unit. The head including a collet body having a pluralityof collet segments collectively forming a cylindrical outer perimeterhaving a variable diameter, each collet segment having a threadedsurface on the outer perimeter such that the actuator unit canselectively vary the diameter of the outer perimeter.

It is an object of the present invention to provide a hydrostatictesting tool that may be quickly secured and unsecured to a threadedaperture of a test article, such as a container, hose or the like. It isanother object of the present invention to provide a hydrostatic testingtool that is durable, provides a reliable seal and cannot becomedislodged from the threaded aperture during testing.

Preferred embodiments of the present invention achieve these and otherobjectives by providing a hydrostatic testing tool including acontainer-engaging head. The head preferably includes a generallycylindrical attachment body that is connected to an actuator unit havinga central channel. The actuator unit preferably has a rear end where aninlet aperture can be sealably attached, in any known way, to a sourceof high-pressure fluid such as, gas, liquid or the like, preferablyliquid, during testing. The pressurized fluid entering the inletaperture preferably flows along the central channel toward the head ofthe tool.

The head of preferred embodiments further includes a longitudinallyextending central chamber which communicates with the central channel ofthe actuator unit. The head of preferred embodiments additionally has ahollow cylindrical sleeve which is slidably received into, and containedwithin, the chamber. The sleeve is retained within the chamber by aretaining snap ring after being slid into the chamber from the front endof the head.

The head of preferred embodiments further includes an attachment bodythat houses a collet body of generally cylindrical configuration whichis inserted into the chamber of the head from the rear end of the headbefore the head is threaded onto the actuator unit. The collet body ofpreferred embodiments includes a plurality of collet segments having acylindrical outer perimeter. The collet segments of preferredembodiments are somewhat pie wedge shaped in cross section, moveablerelative to each other and fit together to generally form a cylindricalshape. All of the collet segments, when properly aligned with eachother, cooperate to define a generally continuous thread around thecylindrical outer perimeter that corresponds to or mates with thethreaded aperture of the test article.

The collet body of preferred embodiments further includes an annularring slot near its rearmost end. A removable two-piece split lock ringis slipped into the ring slot of preferred embodiments and helps lockthe collet body in place relative to the attachment body. The front ofthe actuator unit of this embodiment bears against the two-piece lockring when the actuator unit is connected to the head. In essence, thetwo-piece ring restricts (but does not wholly prevent) the collet bodyfrom moving forward, and the actuator unit restricts (but does notwholly prevent) the collet body and the lock ring from moving rearward.The ability of the collet segments to move forward and rearward, howeverslight, allows the collet segments to slightly adjust their longitudinalpositions relative to one another to align with the threaded aperture.The collet body of this embodiment has an internal longitudinal channelextending rearwardly along its central axis from the front of the colletbody and communicating with the actuator unit channel. A sliding piston,which is retained and selectively controlled by the actuator unit, canmove forward and rearward along the central axis of the channel toradially expand the collet segments outwardly to engage the threadedaperture. In preferred embodiments, the testing tool further includes asleeve or knurled knob, such that when the knob is rotated, the sealbetween the testing tool and the test article is enhanced.

The piston of this embodiment includes an internal piston channelextending from its rear end and communicating with the central channel.The piston channel ends midway along the piston where two smaller pistonports extend forwardly and outward to the outer periphery of the pistonto allow pressurized fluid material, such as gas or liquid, to flow fromthe piston channel and along the piston ports to reach the colletsegments.

Referring again to the channel formed along a central longitudinal axisof the collet body of this embodiment, the sliding piston is positionedwithin the channel for forward and rearward movement along the centralaxis of the collet body. As the piston moves forward, an annularshoulder of the piston contacts shoulders of the collet segments andpushes the collet segments radially outward from the central axis froman initial rest or unexpanded position to an expanded position, causingthe diameter of the cylindrical outer perimeter of the threaded colletsegments to increase uniformly along the collet body length so that thethreaded collet segments strongly, mateably and evenly engage thethreaded aperture so as to reliably seal the junction between thetesting tool and the test article and retain the test article duringhigh pressure testing.

The collet body of preferred embodiments additionally has front and rearannular slots each retaining a biasing device, such as a stretchableO-ring, snap ring or the like, that applies a force to urge the colletsegments radially inward and together so as to retain and return thecollet segments to an initial, unexpanded position. When the colletsegments of preferred embodiment are in the unexpanded position, thecylindrical outer perimeter diameter is small enough to allow the colletsegments to slide longitudinally within the threaded aperture of thecontainer. When the collet segments are in a radially expanded position,the diameter of the cylindrical outer perimeter is increased to closelymatch, tightly engage and retain the threaded aperture.

When the collet segments of the preferred embodiment are in a radiallyexpanded position, there is a gap created between each collet segmentthat reduces the risk of the fluid material flow path becomingobstructed and allows pressurized fluid material, preferably liquid, toflow through the gaps to enter into the test article.

The biasing devices of preferred embodiments allow the separate colletsegments to move forwardly or rearwardly, slightly and independently ofeach other so as to permit the respective threaded surfaces toindependently self-align with the threaded aperture and to more readilyengage the threaded aperture when portions of the threaded aperture aresomewhat irregular or damaged.

A wave spring is positioned within the central chamber preferredembodiments and extends between a rear shoulder of the head and anoutwardly extending annular sleeve flange on the sleeve to spring biasthe sleeve forwardly toward and against the retaining snap ring. At thefront end of the sleeve is a sleeve slot in which a sealing O-ringresides in preferred embodiments. The wave spring and the sealing O-ringdevices play an important role in creating an effective seal between thefront end of the testing tool and the container or other test article.

When a container or other test article is to be tested, the colletsegments of preferred embodiments are placed in an unexpanded position.The unexpanded collet segments can then be inserted into the threadedaperture of the container. As the testing tool is pressed against thecontainer, the sleeve is pushed rearwardly by the container against thewave spring of preferred embodiments so as to cause the wave spring tobias the sleeve against the container. At this time, the actuator unitis activated to force the piston forward and into the collet body,causing the collet segments to move radially outward to an expandedposition and solidly, threadably engage the threaded aperture of thecontainer. Because the wave spring is now forcing the sleeve against thecontainer, the sleeve O-ring in the front slot becomes compressed. Atthe contact circle between the container and the sleeve, the O-ring inthe front slot is compressed between the container, the sleeve and thecollet body to form a tight seal.

Preferably, the annular front slot has an angled front wall that slantsrearwardly to better retain the O-ring and prevent it from escaping fromthe front slot during the forward and rearward movement of the sleeverelative to the O-ring. When the pressure is applied to the testing toolof preferred embodiments, the pressure also cooperates with the wavespring, sleeve and the container to force the O-ring against thecontainer and further improve the seal therebetween.

The testing tool and methods of preferred embodiments of the presentinvention are much faster and easier to use than known methods thatemploy rotating a threaded end of the testing tool into the threadedaperture of the test article to produce a tight seal. Although thatprior method works, it is time consuming to have to thread and unthreadthe testing tool from the threaded aperture and, assuming it is not doneby hand, which would be really slow, it also requires complex automaticequipment to do the threading and unthreading needed to connect the toolto the large quantity of test articles that are typically tested in agiven time interval.

The testing tool and methods of the present invention are also muchsafer and more reliable than the known expandable rubber plug methodthat involves inserting a rubber plug into the threaded aperture of thecontainer and to then mechanically expanding the plug to sealably engagethe threaded aperture. This known rubber plug method, when used at highpressures, has been unreliable and has created safety problems in thatas the rubber plug wears, the container can sometimes slip off therubber plug. When it does slip off, the container may be “launched” athigh speed from the plug as the high pressure fluid within the containerunder test is released, resulting in a flying container that canendanger anyone or anything in its path.

These and various other advantages and features of novelty whichcharacterize the present invention are pointed out with particularity inthe claims annexed hereto and forming a part hereof. However, for abetter understanding of the invention, its advantages and objectsobtained by its use, reference should be made to the drawings ofpreferred embodiments of the present invention, which form a furtherpart hereof, and to the accompanying descriptive matter, in which thereis illustrated and described preferred embodiments of the presentinvention.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings, in which corresponding reference numerals and lettersindicate corresponding parts of the various embodiments throughout theseveral views, and in which the various embodiments generally differonly in the manner described and/or shown, but otherwise includecorresponding parts;

FIG. 1A is a perspective view of a preferred hydrostatic testing tool 10of the present invention in an unexpanded position;

FIG. 1B is a side view of the testing tool 10 of FIG. 1A;

FIG. 2A is a perspective view, similar to that of FIG. 1A, of thetesting tool 10 of FIGS. 1A-1B, illustrating the testing tool in anexpanded position;

FIG. 2B is a side view of the testing tool 10 shown in FIG. 2A;

FIG. 3 is a partial, cross-sectional view of the testing tool 10 asviewed along line 3-3 of FIG. 2B, illustrating the interior componentsof the testing tool including an actuator unit 12 having a centralchannel 18 that is interconnected to a head 40 having a collet body 66with a channel 68 that is surrounded by a sleeve 52; and a piston 100operatively connected within the actuator or central channel 18 and thecollet channel 68 but showing the entire wave spring 112 as it would beseen from line 3-3 and not showing threaded fittings of the embodimentillustrated in FIG. 1A;

FIG. 4 is an expanded cross-sectional view of the collet body 66 of FIG.3 illustrating the collet channel 68;

FIG. 5 is an expanded cross-sectional view of the piston 100 of FIG. 3;

FIG. 6 is an expanded cross-sectional view of the sleeve 52 of FIG. 3;

FIG. 7 is a partially exploded, perspective view of the testing tool 10of FIGS. 1A-1B illustrating the actuator unit 12 and acontainer-engaging head 40;

FIG. 8 is an end view of a rear end 44 of the container-engaging head 40of FIG. 7;

FIG. 9A is a perspective view of a preferred alternate hydrostatictesting tool 10′ in an expanded position;

FIG. 9B is side view of the testing tool 10′ of FIG. 9A;

FIG. 10 is a cross-sectional view of the testing tool 10′ as viewedalong line 10-10 of FIG. 9B;

FIG. 11 is a perspective view of the testing tool 10′ before insertioninto a threaded aperture T of a container C that is to be tested;

FIG. 12A is a cross-sectional view of the testing tool 10′ of FIG. 11 asit is inserted into the threaded aperture T in the unexpanded position;and

FIG. 12B is a cross sectional view of the testing tool 10′ of FIGS.11-12A, when the testing tool 10′ is in the expanded position.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Preferred embodiments of the present invention are illustrated in FIGS.1-12B. Referring in particular now to FIGS. 1-3 and 7-8, one embodimentof a hydrostatic testing tool 10 includes an actuator unit 12interconnected to an article or container-engaging head 40. The head 40is a generally cylindrical structure that includes a front end 42, arear end 44 and an attachment body 48 which threads onto the actuatorunit 12 at junction 50. The actuator unit 12 has a rear end 14 and atthe rear end 14 is an inlet aperture 16 that is sealably attached in anyknown way to a source of high-pressurized fluid material (not shown),preferably liquid, for testing. It should be understood that althoughthe inlet aperture 16 is described as for receiving liquid, the testingtool 10 of the present invention will work with gases as well. Thepressurized liquid entering inlet aperture 16 flows along a centralchannel 18 in a direction towards the head 40. It will be appreciatedthat the container engaging head can engage test articles other thancontainers and the present invention is not, therefore, limited to usewith any particular test articles.

Referring in particular now to FIGS. 1A and 3-5, the head 40, furtherhas a longitudinally extending central chamber 68 that communicates withthe channel 18 of the actuator unit 12. The head 40 also includes ahollow cylindrical sleeve 52, which is slidably received into andcontained within the chamber 64. The sleeve 52 is preferably retainedwithin the chamber 64 by a retaining, snap ring 54 or the like, afterthe sleeve 52 is slid into the chamber 64 from the front end 42 of thehead 40.

The head 40 further includes a generally cylindrical collet body 66 thatis inserted into the chamber 68 from the rear end 44 of the head 40before the head is connected, preferably threadably attached, to theactuator unit 12. The preferred collet body 66 has a plurality of colletsegments 70 and an annular ring slot 84 near its rear end. A removabletwo-piece split lock ring 86 is slipped into the ring slot 84 and helpslock the collet body 66 in place relative to the attachment body 48. Theactuator unit 12 bears against the two-piece split lock ring 86 when theactuator unit 12 is connected to the head 40. In essence, the split lockring 86 restricts (but does not wholly prevent) the collet body 66 frommoving forward, and the actuator unit 12 restricts (but does not whollyprevent) the collet body 66 and the split lock ring 86 from movingrearward. Such forward and rearward movement, however slight, allows thecollet segments 70 to slightly adjust their longitudinal positionsrelative to one another. The collet body 66 has an internal longitudinalchamber 68 extending rearwardly along its central axis from the front ofthe collet body 66 and communicates with the actuator unit channel 18. Asliding piston 100, which is retained and selectively controlled by theactuator unit 12, moves forward and rearward along the central axis ofthe collet channel 68 to radially expand the collet body 66 inward andoutward, as is described in more detail below.

The piston 100 has an internal piston channel 102 extending from itsrear end and communicating with the central channel 18. The channel 102ends midway along the piston 100 at the channel end 104 where twosmaller piston ports 106 extend forwardly and outward to the outerperiphery of the piston 100 to allow pressurized liquid to flow from thechannel 102 and along the ports 106 to reach the collet body 66. Aspring 114 maintains contact between the actuator assembly 22 and therear body 14 for extending and retracting of the piston 100 from thecollet body 66. Extending the piston 100 causes the collet body 66 toexpand and grip the threaded aperture T of a test article or containerC, while retracting the piston 100 allows the collet body 66 toconstrict and release its grip on the threaded aperture T.

The preferred collet body 66 has six collet segments 70, which aresomewhat pie wedge shaped in cross-section, moveable relative to eachother and which fit together to from a cylindrical outer perimeter 72having a diameter “D”. Each of the collet segments 70 has a threadedsurface 76 around the cylindrical outer perimeter 72 near its front end78 and the threaded surface 76 corresponds to a threaded surfacedefining the threaded aperture T of the test container C (see also, FIG.11). All of the collet segments 70, when properly aligned with eachother, cooperate to define a generally continuous threaded surface 76around the cylindrical outer perimeter 72 of the collet segments 70,which corresponds to the threaded aperture T of the test container C.The generally continuous threaded surface 76 is separated by the areabetween the respective collet segments 70.

Referring again to the channel 68 formed along the central longitudinalaxis of the collet body 66, the sliding piston 100 is positioned withinthe channel 68 and the chamber 64 for forward and rearward movementalong the central axis of the collet body 66. Referring now also toFIGS. 3-6, as the piston 100 moves forward, an annular shoulder 108 ofthe piston 100 contacts shoulders 80 and 82, respectively on the colletsegments 70 (see, FIG. 4) and pushes the collet segments 70 radiallyoutward from the central axis from an initial rest or unexpandedposition (see FIG. 1B) to an expanded position (see FIG. 2B), causingthe unexpanded diameter “D” of the cylindrical outer perimeter 72 toincrease uniformly to a second diameter “D2” so that the threaded colletsegments 70 strongly, mateably and evenly engages the threaded apertureT so as to reliably retain the container C on the testing tool 10 duringhigh pressure testing.

The preferred actuator unit 12 is illustrated in FIGS. 1-3. FIGS. 1A and1B show the preferred actuator unit 12 further including a body 20interconnected to an actuator assembly 22 having a generally cylindricalportion 24 and a lever 28 extending laterally through the generallycylindrical portion 24. Preferably, the generally cylindrical portion 24is interconnected, off-center, to a collar 30 circumscribing a shaft 32that is operatively connected to the piston 100. The preferred generallycylindrical portion 24 includes a recess 26 such that when the lever 28is rotated, the generally cylindrical portion 24 correspondinglyrotates. As shown in FIGS. 1A and 1B, when the generally cylindricalportion 24 is rotated far enough such that the body 20 enters the recess26, the collar 30 and the shaft 32, are pushed rearwardly, thus movingthe piston 100 (see FIG. 3) rearwardly as well and placing the colletsegments 70 in the unexpanded position. As shown in FIGS. 2A and 2B,when the lever 28 is further rotated as to forcedly position the body 20outside of the recess 26, the collar 30 and the shaft 32, and thus thepiston 100, slide forward and the collet segments 70 move into theengaged position. In preferred embodiments, the generally cylindricalportion 24 will include two recesses 26 approximately 180 degrees fromeach other so that generally cylindrical portion 24 requires lessrotation to un-expand the collet segments 70. It is noted that this issimply the preferred actuator unit and that any other known plungingdevice can be used to control the movement of the piston. It will beunderstood that the actuating unit can be actuated either mechanicallyor pneumatically.

The collet body 66 is preferably, first formed as an integral,cylindrical stainless steel unit, and the threaded surface 76 is thencut into the outer perimeter 72 near the front end 78 of the collet body66 so as to correspond to the threaded aperture T. The central channel68 is then bored longitudinally through the collet body 66 along thecentral axis, and the shoulders 80 and 82 may be machined within thecollet body 66 during the boring operations. At this stage, the colletbody 66 is cut along three radial planes into the six collet segments70, or, alternatively, as many or as few radial planes as needed tocreate the desired number of collet segments. It should be noted thatthe threaded surface 76 on each collet segment 70 is likely to bedifferent in alignment from the other collet segments, and, therefore,the segments are preferably aligned in the same order as that whichexisted before cutting in order that the threaded surfaces as a wholeretains its original nature on the collet body.

As best shown in FIGS. 3-4, the preferred collet body 66 has front andrear annular slots 88, 90 extending about its outer periphery and abiasing device 92, such as a stretchable O-ring, snap ring or the likeis received into each of the front and rear slots 88, 90 to apply aforce to urge the collet segments 70 radially inward and together so asto retain and return the collet segments 70 to an initial unexpandedposition. When the collet segments 70 are in the unexpanded position,the cylindrical outer perimeter 72 should have a diameter “D” smallenough to allow the threaded surfaces 76 to slide longitudinally withinthe threaded aperture T of the container C (see also, FIG. 11). When thecollet segments 70 are in a radially expanded position, the originaldiameter “D” of the cylindrical outer perimeter 72 is increased to thesecond diameter “D2′” that closely matches, tightly engages and retainsthe threaded aperture T. When the collet segments 70 are in a radiallyexpanded position, there is a gap 74 created between each collet segment70 (See FIG. 2A) that reduces the risk of the fluid material or liquidflow path becoming obstructed and allows pressurized liquid to flowthrough the gaps 74 and enter into the container C.

The use of the biasing devices 92 in the front and rear slots 88, 90 ofthe collet body 66 allows the separate segments 70 of the collet body 66to move forwardly or rearwardly, slightly and independently of eachother so as to have their respective threaded surfaces 76 be moreself-aligning with the threaded aperture T and even to more readilyengage the threaded aperture when the threaded aperture may be somewhatirregular or damaged. The preferred biasing device 92 is an O-ring madeof BUNA (nitrile), but the preferred material may vary depending on thesubstance to be pressurized as will be determinable by one of ordinaryskill in the art in light of this disclosure. It will be appreciatedthat O-rings made of other suitable materials may also be used.

Referring now also to FIGS. 3-6, a wave spring 112 is positioned withinthe chamber 64 of the head 40 and extends between a rear shoulder 46 ofthe head 40 and an outwardly extending annular sleeve flange 60 of thesleeve 52 to spring bias the sleeve 52 forwardly toward and against theretaining ring 54. At the front end of the sleeve 52 is a sleeve slot56, which preferably contains a sealing O-ring 62 or the like. The slot56 cross-section is best shown in FIG. 6. The wave spring 112 and theO-ring 62 in the sleeve slot 56 play an important role in creating aneffective seal between the front end of the tool 10 and the containerand are best understood in conjunction with the following description ofhow the tool engages and seals the container.

When a container C is to be tested, the collet segments 70 are placed intheir unexpanded positions so that the collet segments fit within thethreaded aperture T of the test container aperture C. The unexpandedcollet segments 70 are slidably inserted into the threaded aperture ofthe container. As the tool 10 is pressed against the container, thesleeve 52 is pushed rearwardly by the container against the wave spring112 so as to cause the wave spring to bias the sleeve 52 against thecontainer. At this time the actuator unit 12 is activated to force thepiston 100 forward and into the collet body 66, causing the colletsegments 70 to move radially outward to expanded position and solidly,threadably engage the threaded aperture of the container. This resultsin the container being fixed relative to and “locked on” to the colletbody 66. Because the wave spring 112 is forcing the sleeve 52 againstthe container, the O-ring 62 in the sleeve slot 56 becomes compressed.At the contact circle between the container and the sleeve 52, theO-ring 62 is compressed between the container, the sleeve 52 and thecollet body 66 to form a tight seal.

As best shown in FIG. 6, the sleeve slot 56 has an angled front wall 58that slants rearwardly to better retain the O-ring 62 and prevent theO-ring from escaping from the sleeve slot 56 during the forward andrearward movement of the sleeve 52 relative to the O-ring 62. When thepressure is applied to the tool 10, the pressure also cooperates withthe wave spring 112, sleeve 52 and the container to force the O-ring 62against the container and further improve the seal therebetween.

Referring again to FIG. 3, the preferred testing tool 10 furtherincludes a plurality of O-rings 94 positioned throughout the actuatorunit 12 and the head 40. These O-rings 94 function as seals for theactuation of the internal parts of the tool 10 and their placement andusage will be apparent to one of ordinary skill in the art in light ofthis disclosure.

FIGS. 9A-10 illustrate another embodiment of a hydrostatic testing tool10′ largely similar to the embodiment illustrated in FIGS. 1-8, whichwas subsequently developed and is believed to be preferred. The testingtool 10′ includes an actuator unit 12′ interconnected to acontainer-engaging head 40′. As in the previous embodiment, the head 40′is a generally cylindrical structure that includes a front end 42′, arear end 44′ and an attachment body 48′ which threads onto the actuatorunit 12′ at junction 50′. The actuator unit 12′ has a rear end 14′ andat the rear end 14′ is an inlet aperture 16′ that is sealably attachedin any known way to a source of high-pressure fluid material such asliquid or gas for testing (see in particular, FIG. 10). The pressurizedliquid or gas entering inlet aperture 16′ flows along a central channel18′ in a direction towards the head 40′.

Referring in particular now to FIG. 10, the head 40′, further has alongitudinally extending central chamber 68′ which communicates with thechannel 18′ of the actuator unit 12′. The head 40′ also includes ahollow cylindrical sleeve 52′ which is slidably received into andcontained within the chamber 64′. The sleeve 52′ is preferably retainedwithin the chamber 68′.

The head 40′ further includes a generally cylindrical collet body 66′that is inserted into the chamber 68′ from the rear end 44′ of the head40′ before the head is connected, preferably threadably attaching, tothe actuator unit 12′. The preferred collet body 66′ has a plurality ofcollet segments 70′ and an annular ring slot 84′ near its rear end. Aremovable two-piece split lock ring 86′ is slipped into the ring slot84′ and helps lock the collet body 66′ in place relative to theattachment body 48′. The actuator unit 12′ bears against the two-piecesplit lock ring 86′ when the actuator unit 12′ is connected to the head40′. In essence, the split lock ring 86′ restricts (but does not whollyprevent) the collet body 66′ from moving forward, and the actuator unit12′ restricts (but does not wholly prevent) the collet body 66′ and thesplit lock ring 86′ from moving rearward. As with the previousembodiment, such forward and rearward movement, allows the colletsegments 70′ to slightly adjust their longitudinal positions relative toone another. The collet body 66′ has an internal longitudinal chamber68′ extending rearwardly along its central axis from the front of thecollet body 66′ and communicates with the actuator unit channel 18′. Asliding piston 100′, which is retained and selectively controlled by theactuator unit 12′, moves forward and rearward along the central axis ofthe collet channel 68′ to radially expand the collet body 66′ inward andoutward.

The piston 100′ has an internal piston channel 102′ extending from itsrear end and communicating with the central channel 18′. The channel102′ ends midway along the piston 100′ at the channel end 104′ where twosmaller piston ports 106′ extend forwardly and outward to the outerperiphery of the piston 100′ to allow pressurized liquid to flow fromthe channel 102′ and along the ports 106′ to reach the collet body 66′.A spring 114′ maintains contact between the actuator assembly 22′ andthe rear body 14′ for extending and retracting of the piston 100′ fromthe collet body 66′. Extending the piston 100′ causes the collet body66′ to expand and grip the threaded aperture T of a test article orcontainer C, while retracting the piston 100′ allows the collet body 66′to constrict and release its grip on the threaded aperture T (see also,FIGS. 12A-12B).

As illustrated in FIG. 9A, the preferred collet body 66′ has six colletsegments 70′, which are somewhat pie wedge shaped in cross-section,moveable relative to each other and which fit together to from acylindrical outer perimeter 72′. Each of the collet segments 70′ has athreaded surface 76′ around the cylindrical outer perimeter 72′ near itsfront end and the threaded surface 76′ corresponds to a threaded surfacedefining the threaded aperture T of the test container C (see, FIG. 11).All of the collet segments 70′, when properly aligned with each other,cooperate to define a generally continuous threaded surface 76′ aroundthe cylindrical outer perimeter 72′ of the collet segments 70′, whichcorresponds to the threaded aperture T of the test container C. Thegenerally continuous threaded surface 76′ is separated by the areabetween the respective collet segments 70′.

Referring again to the channel 68′ formed along the central longitudinalaxis of the collet body 66′, the sliding piston 100′ is positionedwithin the channel 68′ and the chamber 64′ for forward and rearwardmovement along the central axis of the collet body 66′. As the piston100′ moves forward, an annular shoulder 108′ of the piston 100′ contactsshoulders 80′ and 82′, respectively on the collet segments 70′ andpushes the collet segments 70′ radially outward from the central axisfrom an initial rest or unexpanded position (see also, FIG. 1A) to anexpanded position (as illustrated in FIG. 9A), causing the unexpandeddiameter of the cylindrical outer perimeter to increase uniformly to asecond diameter so that the threaded collet segments 70′ strongly,mateably and evenly engages the threaded aperture T so as to reliablyretain the container C on the testing tool 10′ during high pressuretesting.

The preferred actuator unit includes a body 20′ interconnected to anactuator assembly 22′ having a generally cylindrical portion 24′ and alever 28′ extending laterally through the generally cylindrical portion24′. Preferably, the generally cylindrical portion 24′ isinterconnected, off-center, to a collar 30′ circumscribing a shaft 32′that is operatively connected to the piston 100′. The preferredgenerally cylindrical portion 24′ includes a recess 26′ such that whenthe lever 28′ is rotated, the generally cylindrical portion 24′correspondingly rotates. When the generally cylindrical portion 24′ isrotated far enough such that the body 20′ enters the recess 26′, thecollar 30′ and the shaft 32′, are pushed rearwardly, thus moving thepiston 100′ rearwardly as well and placing the collet segments 70′ inthe unexpanded position (see also, FIG. 1A). When the lever 28′ isfurther rotated as to forcedly position the body 20′ outside of therecess 26′, the collar 30′ and the shaft 32′, and thus the piston 100′,slide forward and the collet segments 70′ move into the engagedposition. In preferred embodiments, the generally cylindrical portion24′ will include two recesses 26′ approximately 180 degrees from eachother so that generally cylindrical portion 24′ requires less rotationto un-expand the collet segments 70′. As with the previous embodiment,the actuator unit shown is simply the preferred actuator unit and thatany other known plunging device may be used to control the movement ofthe piston. It will be understood that the actuating unit can beactuated either mechanically or pneumatically.

Referring also to FIGS. 10, 12A, and 12B, similar to the previousembodiment, the preferred collet body 66′ has front and rear annularslots 88′, 90′ extending about its outer periphery and a biasing device92′, such as a stretchable O-ring, snap ring or the like is receivedinto each of the front and rear slots 88′, 90′ to apply a force to urgethe collet segments 70′ radially inward and together so as to retain andreturn the collet segments 70′ to an initial unexpanded position. Whenthe collet segments 70′ are in the unexpanded position, the cylindricalouter perimeter 72′ should have a diameter small enough to allow thethreaded surfaces 76′ to slide longitudinally within the threadedaperture T of the test article or container C. When the collet segments70′ are in a radially expanded position, the original diameter of thecylindrical outer perimeter 72′ is increased to the second diameter thatclosely matches, tightly engages and retains the threaded aperture T ofthe container C (see, FIG. 12B). When the collet segments 70′ are in aradially expanded position, there is a gap 74′ created between eachcollet segment 70′ (See FIG. 9A) that reduces the risk of the fluidmaterial flow path becoming obstructed and allows pressurized fluidmaterial to flow through the gaps 74′ and enter into the container C.

The use of the biasing devices 92′ in the front and rear slots 88′, 90′of the collet body 66′ allows the separate segments 70′ of the colletbody 66′ to move forwardly or rearwardly, slightly and independently ofeach other so as to have their respective threaded surfaces 76′ be moreself-aligning with the threaded aperture T and even to more readilyengage the threaded aperture when the threaded aperture is somewhatirregular or damaged.

In this preferred embodiment, the testing tool 10′ further includes aknob 120′. The knob 120′ preferably has a knurled surface 122′ so thatit is easy to grip and rotate. The knob 120′ rotates relative to thefront end 42′ which has internal threads. When a user rotates the knob120′ in the clockwise direction relative to the right end view of thetesting tool 10′, the knob 120′ will move away from end of the front end42′. During use, the knob 120′ is preferably only rotated clockwiseafter the collet body 66′ is securely engaged with the threaded apertureT of the container C. By rotating the knob 120′ clockwise it causes aface seal 62′ retained in the knob 120′ to be pressed against thecontainer C resulting in compression of the face seal 62′ to create aleak tight condition superior to that of the embodiment of FIGS. 1A-8.The force of compressing the face seal 62′ is reacted by the collet body66′ gripping the threaded aperture T. After testing tool 10′ usage wherethe collet segments 70′ of the collet body 66′ are released and notgripping the threaded aperture T, the knob 120′, is rotatedcounterclockwise to reset the knob 120′ for the next application.

To further increase the seal between the testing tool 10′ and thecontainer C, the sleeve slot 56′ has an angled front wall 58′ thatslants rearwardly to better retain the face seal or O-ring 62′ andprevent the O-ring from escaping from the sleeve slot 56′ during theforward and rearward movement of the sleeve 52′ relative to the O-ring62′. As also discussed above, when the pressure is applied to the tool10′, the pressure also cooperates with the knob 120′, cylindrical sleeve52′ and the container C to force the O-ring 62′ against the container Cand further improve the seal therebetween.

As with the embodiment of FIGS. 1A-8, the preferred testing tool 10′further includes a plurality of O-rings 94′ or the like positionedthroughout the actuator unit 12′ and the head 40′. These O-rings 94′function as seals for the actuation of the internal parts of the tool10′ and their placement and usage will be apparent to one of ordinaryskill in the art.

Although only a container is illustrated, it will be appreciated thatthe hydrostatic testing tool can be used to test other various testarticles having a threaded aperture, such as a hose or the like.

Although the preferred embodiments of the present invention have beendescribed herein, the above description is merely illustrative. Furthermodification of the invention herein disclosed will occur to thoseskilled in the respective arts and all such modifications are deemed tobe within the scope of the invention as defined by the appended claims.

What is claimed is:
 1. A tool for engaging and retaining an articlehaving a threaded aperture, the tool comprising: a head having a colletbody including at least three collet segments collectively forming acylindrical outer perimeter having a variable perimeter and a centrallongitudinal axis, each collet segment having a threaded surface; and anactuator unit interconnected with the head and constructed and arrangedto selectively vary the diameter of the outer perimeter to selectivelyengage and disengage the threaded aperture of the article.
 2. The toolof claim 1, wherein the actuator unit includes an actuator assemblyhaving a lever; and the lever being movable to selectively vary thediameter of the outer perimeter.
 3. The tool of claim 1, wherein thecollet body further includes: an annular slot located rearward of thethreaded surfaces and extending about the collet body outer perimeter;and a biasing device received into the annular slot to apply a force tourge the collet segments radially inward and together so as to bias thecollet segments in an initial unexpanded condition.
 4. The tool of claim3, further comprising a sliding piston that is retained by the actuatorunit and is selectively movable forwardly within the actuator unit andtoward the head from an initial piston position and cooperating with thebiasing device to move the collet segments to an expanded condition byovercoming the force of the biasing device and permitting the biasingdevice force to return the collet segments to an unexpanded conditionwhen the piston moves rearwardly to the initial piston position.
 5. Thetool of claim 4, wherein the collet segments are moveable parallel tothe longitudinal axis independently of each other to allow the segmentsto longitudinally, independently align their respective threadedsurfaces with the threaded aperture of the article.
 6. The tool of claim1, further comprising a sliding piston that is retained by the actuatorunit and is selectively movable forwardly within the actuator unit andtoward the head from an initial piston position to thereby move thecollet segments from an unexpanded condition to an expanded condition,the collet segments returning to the unexpanded condition when thepiston moves rearwardly to the initial piston position.
 7. The tool ofclaim 1, wherein the collet body includes six collet segments.
 8. Thetool of claim 1, wherein the collet segments are moveable parallel tothe longitudinal axis independently of each other to allow the segmentsto longitudinally, independently align their threaded surfaces with thethreaded aperture of the article.
 9. A tool for engaging and retainingan article having a threaded aperture, the tool comprising: a headhaving a collet body and including a plurality of collet segmentsarranged around a central longitudinal axis, each collet segment havingan outer surface, the outer surfaces of the plurality of collet segmentscollectively forming an outer perimeter constructed and arranged toenter and engage the threaded aperture, the collet segments beingmoveable toward and away from the central axis to cause the size of theouter perimeter to vary when the segments move toward and away from thecentral axis, each collet segment having a thread on at least part ofits outer surface to match and engage the threaded aperture when thecollet segments move outward from the central axis into contact with thethreaded aperture; and an actuator unit interconnected with the head andconstructed and arranged to selectively move the collet segments outwardand inward relative to the central axis to vary the size of the outerperimeter to thereby selectively engage and disengage the threadedaperture of the article.
 10. The tool of claim 9, wherein the actuatorunit further includes an actuator assembly having a lever, wherein thelever can be moved to selectively expand the collet segments.
 11. Thetool of claim 9, further comprising: a sleeve at least partiallypositioned within the head; and a seal retained in the sleeve, whereinrotating the sleeve causes the seal to be pressed against the articleand results in compression of the seal to create a seal between thesleeve and the article.
 12. The tool of claim 9, wherein the collet bodyhas an annular slot extending about its outer perimeter; and a biasingdevice received into the annular slot to apply a force to urge thecollet segments together so as to bias the collet segments in anunexpanded condition.
 13. The tool of claim 12, further comprising asliding piston that is retained by the actuator unit and is selectivelymovable forwardly within the actuator unit and toward the head from aninitial piston position and cooperating with the biasing device to movethe collet segments to an expanded condition by overcoming the force ofthe biasing device and permitting the biasing device force to return thecollet segments to an unexpanded condition when the piston movesrearwardly to the initial piston position.
 14. The tool of claim 9,further comprising a sliding piston that is retained by the actuatorunit and moves forward and rearward within the actuator unit toselectively expand and contract the collet segments.
 15. The tool ofclaim 9, wherein the collet body includes six collet segments.